This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Luminescent (photon emitting) reporters offer different perspectives on cell activity than the more conventional fluorescent reporters [unreadable]the latter requiring an excitation frequency to react. Luminescent reporters, although far less diverse, depend upon and chemical interaction between two molecules where the association is dependent on the target to be measured. In the case being developed here we wish to record the cellular activity of ATP through the photon emitting luciferin/luciferase reaction. Luciferin is membrane permeable and as luciferase is a protein it can targeted and expressed if a suitable vector is available. Acquisition of such vectors, and their testing in our photon counting/imaging systems (see SPID 0094) are the goals of this subproject.